Field of the Invention
Embodiments of the present invention generally relate to a wind turbine elevator.
Description of the Related Art
A wind turbine includes a rotor having a hub and multiple (typically three) blades connected to the hub. The rotor is connected to an input drive shaft of a gearbox. The blades transform wind energy into torque that drives a generator connected to an output shaft of the gearbox. The gearbox steps up the inherently low rotational speed of the rotor for the generator to efficiently convert the rotational mechanical energy to electricity, which is fed into a utility grid. Gearless direct drive wind turbines also exist. The drive shafts, generator, gearbox and other components are typically mounted within a nacelle that is positioned on top of a tower that may be a truss or tubular.
FIG. 1 illustrates a prior art lattice boom crawler crane having just assembled a wind turbine. To assemble the wind turbine, a high capacity lattice boom crane is required to hoist the nacelle on to the tower and then to hoist the rotor on to the nacelle. Since the wind turbines are usually located in remote locations, costs of deploying the crane to the wind turbine site can become substantial. Further, to increase capacity and efficiency, larger towers, longer blades, and heavier nacelles are currently in development, further exacerbating the installation cost (and maintenance cost if the nacelle must be removed) up to the point that it may be cost prohibitive to install the larger wind turbines, especially if the height capacity of the conventional lattice boom crane is exceeded.